firefox will now track your searches by default and you'd have no way of knowing they're doing that unless you look for this random blog post on their website: https://blog.mozilla.org/en/products/firefox/firefox-search-update/
it does look like you can turn it off at least.
@hi_mayank They are very busy within the whole Mozzilla Foundation. They don't get all their income from partnering with Google anymore. They have their own vision... or version.